Method of allocating resources for transmitting uplink signal in MIMO wireless communication system and apparatus thereof

ABSTRACT

A method and terminal apparatus are described for allocating resources for transmitting a signal in a multiple-input multiple-output (MIMO) wireless communication system. An uplink signal is transmitted using L layers at a terminal in a multiple-input multiple-output (MIMO) wireless communication system. Modulation symbols are generated by modulating output bit sequences of an interleaver matrix by a unit of log 2  Q bits. Q is a modulation order, and each of the output bit sequences has a size of L·log 2  Q bits. The modulation symbols are mapped to the L layers and transmitted by using the L layers. The output bit sequences are generated by reading out entries of the interleaver matrix, column by column.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 14/199,865 filed on Mar. 6, 2014, which is a continuation ofU.S. patent application Ser. No. 13/147,076 filed on Sep. 23, 2011 (nowU.S. Pat. No. 8,699,314), which is the national phase of PCTInternational Application No. PCT/KR2010/000599 filed on Feb. 1, 2010,which claims the benefit of U.S. Provisional Application Nos. 61/149,009filed on Feb. 1, 2009, 61/151,839 filed on Feb. 11, 2009, 61/152,271filed on Feb. 13, 2009, 61/152,948 filed on Feb. 16, 2009, 61/179,003filed on May 17, 2009, and Korean Patent Application No. 10-2010-0008931filed on Feb. 1, 2010. The contents of all of these applications arehereby incorporated by reference as fully set forth herein in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wireless communication system, andmore particularly, to a method of allocating resources for transmittingan uplink signal in a Multiple-Input Multiple-Output (MIMO) wirelesscommunication system and an apparatus thereof.

2. Discussion of the Related Art

In Multiple-Input Multiple-Output (MIMO), multiple transmission antennasand multiple reception antennas are used. By this method, datatransmission/reception efficiency can be improved. That is, since aplurality of antennas is used in a transmitter or a receiver of awireless communication system, capacity can be increased and performancecan be improved. Hereinafter, MIMO may also be called “multi-antenna”.

In the MIMO technique, a single antenna path is not used for receivingone message. Instead, in the MIMO technique, data fragments received viaseveral antennas are collected and combined so as to complete data. Ifthe MIMO technique is used, a data transfer rate may be improved withina cell region having a specific size or system coverage may be increasedwhile ensuring a specific data transfer rate. In addition, thistechnique may be widely used in a mobile communication terminal, arepeater and the like. According to the MIMO technique, it is possibleto overcome a limit in transmission amount of conventional mobilecommunication using a single antenna.

The configuration of the general multi-antenna (MIMO) communicationsystem is shown in FIG. 1. N_(T) transmission antennas are provided in atransmitter and N_(R) reception antennas are provided in a receiver. Ifthe multiple antennas are used in both the transmitter and the receiver,theoretical channel transmission capacity is increased as compared withthe case where multiple antennas are used in only one of the transmitteror the receiver. The increase of the channel transmission capacity isproportional to the number of antennas. Accordingly, transfer rate isimproved and frequency efficiency is improved. If a maximum transferrate in the case where one antenna is used is R_(o), a transfer rate inthe case where multiple antennas are used can be theoretically increasedby a value obtained by multiplying R_(o) by a rate increase ratio R_(i).Here, R_(i) is the smaller of the two values N_(T) and N_(R).

For example, in a MIMO communication system using four transmissionantennas and four reception antennas, a transfer rate which is fourtimes that of a single antenna system can be theoretically acquired.After the theoretical capacity increase of the MIMO system was proved inthe mid-90s, researched into various techniques of substantiallyimproving a data transfer rate has been actively conducted up to now.Among them, some techniques have already been applied to variouswireless communication standards of third-generation mobilecommunication and a next-generation wireless Local Area Network (LAN).

The MIMO technique may be divided into a spatial diversity scheme forincreasing transmission reliability using the same symbols passingthrough various channel paths and a spatial multiplexing scheme fortransmitting a plurality of different data symbols using a plurality oftransmission antennas so as to improve a transfer rate. In addition,these schemes are adequately combined so as to obtain respective merits.

In association with the MIMO technique, various research such asinformation theory associated with MIMO communication capacitycomputation in various channel environments and multiple accessenvironments, research on radio channel measurement and model derivationof the MIMO system, and space-time signal processing technology forimproving a transfer rate and improving transmission reliability havebeen actively conducted.

SUMMARY OF THE INVENTION

An object of the present invention devised to solve the problem lies ona method of allocating resources for transmitting an uplink signal in aMultiple-Input Multiple-Output (MIMO) wireless communication system andan apparatus thereof.

The object of the present invention can be achieved by providing amethod of allocating resources for enabling a terminal to transmit asignal in a Multiple-Input Multiple-Output (MIMO) wireless communicationsystem, the method including: allocating one or more spatial resourcesof a plurality of spatial resources corresponding to first SingleCarrier-Frequency Division Multiple Access (SC-FDMA) symbols to a firsttransport block; allocating one or more other spatial resources of theplurality of spatial resources corresponding to the first SC-FDMAsymbols to a second transport block; and allocating spatial resourcescorresponding to second SC-FDMA symbols to the first transport block andthe second transport block.

The one or more spatial resources may include a first spatial resourceand a second spatial resource and the one or more other spatialresources may include a third spatial resource and a fourth spatialresource.

The allocating of the one or more spatial resources of the plurality ofspatial resources may include allocating a first frequency resourceincluded in the first spatial resource and a first frequency resourceincluded in the second spatial resource to the first transport block,and the allocating of the one or more other spatial resources of theplurality of spatial resources may include allocating a first frequencyresource included in the third spatial resource and a first frequencyresource included in the fourth spatial resource to the second transportblock.

If all the first frequency resources included in a subframe of aspecific unit are allocated, the allocating of the first spatialresource and the second spatial resource may include allocating a secondfrequency resource included in the first spatial resource and a secondfrequency resource included in the second spatial resource to the firsttransport block, and the allocating of the third spatial resource andthe fourth spatial resource may include allocating a second frequencyresource included in the third spatial resource and a second frequencyresource included in the fourth spatial resource to the second transportblock.

The spatial resources allocated to the first transport block and thesecond transport block may be shifted in the unit of a predeterminednumber of spatial resources, as the number of SC-FDMA symbols isincreased. The unit of the predetermined number of spatial resources maybe the unit of one layer or two layers.

In another aspect of the present invention, provided herein is aterminal apparatus of a Multiple-Input Multiple-Output (MIMO) wirelesscommunication system, the terminal apparatus including: a processorconfigured to allocate one or more spatial resources of a plurality ofspatial resources corresponding to first Single Carrier-FrequencyDivision Multiple Access (SC-FDMA) symbols to a first transport block,to allocate one or more other spatial resources of the plurality ofspatial resources corresponding to the first SC-FDMA symbols to a secondtransport block, and to allocate spatial resources corresponding tosecond SC-FDMA symbols to the first transport block and the secondtransport block; and a transmission module configured to transmit thefirst transport block and the second transport block using the allocatedresources through a MIMO antenna.

The one or more spatial resources may include a first spatial resourceand a second spatial resource and the one or more other spatialresources may include a third spatial resource and a fourth spatialresource.

The processor may allocate a first frequency resource included in thefirst spatial resource and a first frequency resource included in thesecond spatial resource to the first transport block if the firstspatial resource and the second spatial resource are allocated to thefirst transport block, and allocate a first frequency resource includedin the third spatial resource and a first frequency resource included inthe fourth spatial resource to the second transport block if the thirdspatial resource and the fourth spatial resource are allocated to thesecond transport block.

In the case where all the first frequency resources included in asubframe of a specific unit are allocated, the processor may allocate asecond frequency resource included in the first spatial resource and asecond frequency resource included in the second spatial resource to thefirst transport block if the first spatial resource and the secondspatial resource are allocated to the first transport block, andallocate a second frequency resource included in the third spatialresource and a second frequency resource included in the fourth spatialresource to the second transport block if the third spatial resource andthe fourth spatial resource are allocated to the second transport block.

The processor may shift the spatial resources allocated to the firsttransport block and the second transport block in the unit of apredetermined number of spatial resources, as the number of SC-FDMAsymbols is increased. The processor may perform shifting in the unit ofone layer or two layers.

According to the embodiments of the present invention, a terminal canefficiently transmit a signal to a base station in a MIMO wirelesscommunication system.

The effects obtained by the embodiments of the present invention are notlimited to the above-described effects, and other effects thereof willbe more clearly derived and understood by those skilled in the art fromthe detailed description of the embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 is a diagram showing the configuration of a generalMultiple-Input Multiple-Output (MIMO) communication system.

FIG. 2 is a diagram showing the architecture of a radio frame used in aLong Term Evolution (LTE) system.

FIG. 3 is a diagram showing the architecture of an uplink subframe usedin an LTE system.

FIG. 4 is a diagram illustrating a process of multiplexing data andcontrol information to be transmitted in uplink.

FIG. 5 is a flowchart illustrating a method of segmenting an informationpart and a parity part of an encoded code block so as to perform ratematching.

FIG. 6 is a diagram illustrating a signal processing procedure of, at aterminal, transmitting an uplink signal in a general wirelesscommunication system.

FIG. 7 is a diagram illustrating a mapping relationship among codewords,layers and antennas for transmitting data as an uplink signal in a MIMOwireless communication system.

FIG. 8 is a diagram illustrating various methods of mapping codewords tolayers.

FIG. 9 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a single codeword scheme is used.

FIG. 10 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a multi-codeword scheme is used.

FIG. 11 is a diagram showing another example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a multi-codeword scheme is used.

FIGS. 12A and 12B are diagrams showing examples of a method ofallocating resources to an uplink signal according to an embodiment ofthe present invention, in the case where the number of transmissionantennas is four and a single codeword scheme is used.

FIG. 13 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is fourand a multi-codeword scheme is used.

FIG. 14 is a diagram showing an example of a resource allocation methodaccording to an embodiment of the present invention, in the case whereeach of two transport blocks is segmented into three code blocks, isencoded and is transmitted with Rank 4.

FIG. 15 is a diagram showing another example of a resource allocationmethod, in the case where each of two transport blocks is segmented intothree code blocks, is encoded and is transmitted with Rank 4.

FIG. 16 is a conceptual diagram of data processing of a system usingmultiple transmission/reception antennas.

FIG. 17 is a diagram showing spatial distribution for transmitting datastreams in uplink in a MIMO system according to an embodiment of thepresent invention.

FIG. 18 is a diagram showing the configuration of a terminal apparatusaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the preferred embodiments of the present invention will bedescribed with reference to the accompanying drawings. It is to beunderstood that the detailed description which will be disclosed alongwith the accompanying drawings is intended to describe the exemplaryembodiments of the present invention, and is not intended to describe aunique embodiment through which the present invention can be carriedout. Hereinafter, the detailed description includes detailed matters toprovide full understanding of the present invention. However, it will beapparent to those skilled in the art that the present invention can becarried out without the detailed matters. For instance, although thefollowing detailed description is made on the assumption that the mobilecommunication system is a 3GPP LTE system, it is applicable to otherprescribed mobile communication systems by excluding unique items of the3GPP LTE.

In some instances, well-known structures and devices are omitted inorder to avoid obscuring the concepts of the present invention and theimportant functions of the structures and devices are shown in blockdiagram form. The same reference numbers will be used throughout thedrawings to refer to the same or like parts.

In the following description, it is assumed that a terminal is a genericterm for a mobile or fixed user-end device such as a user equipment(UE), a mobile station (MS) and the like. In addition, it is assumedthat a base station is a generic name for any node of a network end,which communicates with a terminal, such as a Node B, an eNode B and thelike. In addition, in the present invention, it is noted that atransport block and a codeword have the same meaning.

FIG. 2 is a diagram showing the architecture of a radio frame used in aLong Term Evolution (LTE) system.

Referring to FIG. 2, the radio frame has a length of 10 ms(327200·T_(s)) and includes 10 subframes with the same size. Each of thesubframes has a length of 1 ms and includes two slots. Each of the slotshas a length of 0.5 ms (15360·T_(s)). T_(s) denotes a sampling time, andis represented by T_(s)=1/(15 kHz×2048)=3.2552×10⁻⁸ (about 33 ns). Eachslot includes a plurality of Orthogonal Frequency Division Multiplexing(OFDM) symbols in a time domain, and includes a plurality of ResourceBlocks (RBs) in a frequency domain. In the LTE system, one RB includes12 subcarriers×7(6) OFDM symbols. A Transmission Time Interval (TTI)which is a unit time for transmission of data may be determined in theunit of one or more subframes. The architecture of the radio frame isonly exemplary and the number of subframes included in the radio frame,the number of slots included in the subframe, or the number of OFDMsymbols included in the slot may be variously changed.

FIG. 3 is a diagram showing the architecture of an uplink subframe usedin an LTE system.

Referring to FIG. 3, a subframe 300 having a length of 1 ms which is abasic unit of LTE uplink transmission includes two slots 301 with alength of 0.5 ms. In the case of a length of a normal Cyclic Prefix(CP), each slot includes 7 symbols 302 and one symbol corresponds to oneSingle carrier-Frequency Division Multiple Access (SC-FDMA) symbol. AnRB 303 is a resource allocation unit corresponding to 12 subcarriers ina frequency domain and one slot in a time domain. The architecture ofthe uplink subframe of the LTE system is roughly divided into a dataregion 304 and a control region 305. The data region refers to a seriesof communication resources used for transmission of data, such as voiceor packets transmitted to each terminal, and corresponds to remainingresources excluding the control region within a subframe. The controlregion refers to a series of communication resources used fortransmitting a downlink channel quality report from each terminal,reception ACK/NACK of a downlink signal, uplink scheduling requests orthe like.

FIG. 4 is a diagram illustrating a process of multiplexing data andcontrol information to be transmitted in uplink.

As shown in FIG. 4, in multiplexing of the data with the controlinformation, a Transport Block (TB) Cyclic Redundancy Check (CRC) isattached to a TB to be transmitted in uplink (S401), the TB is segmentedinto several code blocks (CBs) according to the size of the TB (S402),and a CB CRC is attached to each of the several CBs (S403). The resultvalues are subjected to channel coding (S404). In addition, thechannel-coded data is subjected to rate matching (S405), the CBs areconcatenated (S406), and the concatenated CBs are multiplexed withcontrol signals (S407).

Meanwhile, a CRC is attached to Channel Quality Information(CQI)/Precoding Matrix Index (PMI) (S408) and the CQI/PMI is subjectedto channel coding, separately from the data (S409). The channel-codedCQI/PMI is subjected to rate matching (S410) and is multiplexed with thedata (407).

In addition, a Rank Indicator (RI) is subjected to channel coding,separately from the data (S411). The channel-coded RI is subjected torate matching (s412) and is multiplexed with the data (S407).

The multiplexed data, CQI/PMI and RI are subjected to channelinterleaving (S413).

ACK/NACK information is subjected to channel coding, separately from thedata, the CQI/PMI and the RI (S414). The ACK/NACK information isinserted into a portion of the interleaved signals by a puncturingprocess, and the interleaved signals into which the ACK/NACK informationis inserted are mapped to physical resources (S415) and are subjected tosignal processing for uplink transmission.

Meanwhile, in a mobile communication system, for reliable transmission,a transmitter performs channel coding. In this case, a receiver performscoding with respect to information transmitted from the transmitterusing a forward error correction code and transmits the codedinformation, in order to correct a signal error which occurs in achannel. The receiver demodulates the received signal and performs adecoding process on the forward error correction code so as to restorethe transmitted information. The receiver corrects the error of thereceived signal, which occurs in the channel, in the decoding process.

Various types of forward error correction codes may be used, but, in thepresent invention, for example, a turbo code will be described. Theturbo encoder includes a Recursive Systematic Convolution (RSC) encoderand an interleaver. It is known that, as the size of an input data blockis increased, the performance of the turbo encoder is improved. In anactual wireless communication system, for convenience of implementation,a data block having a predetermined size or more is segmented intoseveral small data blocks and coding is performed. The segmented smalldata block is called a code block. Code blocks generally have the samesize, but one code block may have a size different from that of theother code blocks due to a limit in size of the interleaver. When onedata block is divided into two or more code blocks, a CRC may be addedto each of the code blocks for error detection.

The RSC encoder performs a forward error correction coding processaccording to the predetermined size of the interleaver, that is, in thecode block units. Then, the interleaver performs interleaving in orderto reduce influence of a burst error occurring upon transmission of thesignal through a radio channel. Then, the signal is transmitted in astate of being mapped to the radio resources.

Since the amount of radio resources used for actual transmission isconstant, the encoded code block should be subjected to rate matching.In general, rate matching includes puncturing or repetition. Ratematching may be performed in the encoded code block units. As anothermethod, the encoded code block may be segmented into an information(systematic data) part and a parity bit part and the segmented parts maybe separately subjected to rate matching. FIG. 5 is a flowchartillustrating a method of segmenting an information part and a paritypart of an encoded code block so as to perform rate matching. In FIG. 5,it is assumed that a code rate is 1/3.

FIG. 6 is a diagram illustrating a signal processing procedure of, at aterminal, transmitting an uplink signal in a general wirelesscommunication system.

For uplink signal transmission, a scrambling module 601 of a terminalmay scramble a transmitted signal using a terminal-specific scramblingsignal. The scrambled signal is input to a modulation mapper 602 so asto be modulated to complex symbols using a Binary Phase Shift Keying(BPSK), Quadrature Phase Shift Keying (QPSK) or 16 Quadrature AmplitudeModulation (16QAM) scheme according to the type of the transmittedsignal and/or a channel status. Thereafter, the modulated complexsymbols are spread by a transform precoder 603 corresponding to DFTspreading so as to be input to a resource element mapper 604. Theresource element mapper 604 may map the complex symbols totime-frequency resource elements to be used for actual transmission. Theprocessed signals may be input to a SC-FDMA signal generator 605 and maybe transmitted to a base station through an antenna.

FIG. 7 is a diagram illustrating a mapping relationship among codewords,layers and antennas for transmitting data as an uplink signal in a MIMOwireless communication system.

Referring to FIG. 7, there is a complicated mapping relationship betweendata information and transport symbols. A Medium Access Control (MAC)layer transfers N_(c) TBs to a physical layer as data information. Inthe physical layer, the TBs are transformed into codewords by a channelcoding process, and are subjected to a rate matching process such as apuncturing or repetition process. The channel coding process isperformed by a channel coder such as a turbo encoder or a tail bitconvolution encoder.

After the channel coding process and the rate matching process areperformed, N_(c) codewords are mapped to N_(L) layers. The layers referto different information transmitted using the MIMO technique, and thenumber of layers is not greater than Rank which is the maximum number ofpieces of different transmittable information. This may be expressed by# of Layers≦rank(H)≦min(N_(T),N_(R)). Here, H denotes a channel matrix,N_(T) denotes the number of transmission antennas, and N_(R) denotes thenumber of reception antennas.

Unlike an Orthogonal Frequency Division Multiple Access (OFDMA)transmission scheme which is a general downlink transmission scheme, anuplink signal transmitted using an SC-FDMA scheme is subjected to aDiscrete Fourier Transform (DFT) process with respect to each layer,such that the transmitted signal has single carrier characteristics bypartially offsetting the influence of an Inverse Fast Fourier Transform(IFFT) process. The signals which are subjected to the DFT process inthe respective layers are multiplied by a precoding matrix, are mappedto N_(T) transmission antennas, are subjected to the IFFT process, andare transmitted to the base station.

FIG. 8 is a diagram illustrating various methods of mapping codewords tolayers.

Referring to FIG. 8, there are various methods of mapping codewords tolayers. When MIMO transmission is performed, a transmitter shoulddetermine the number of codewords according to the layers. The numbersof codewords and layers are determined by referring to the number ofdifferent data sequences and the rank of the channel. The transmitterneeds to adequately map the codewords to the layers.

In the present invention, a method of efficiently transmitting an uplinksignal in a MIMO system is suggested. In particular, in the presentinvention, it is assumed that, in the MIMO system, the uplink signal istransmitted using an SC-FDMA scheme.

For reference, in FIGS. 9 to 14, a data sample index of an x axisdenotes an index indicating the order of data samples (modulationvalues) input to the DFT in the SC-FDMA system, and a y axis denotes anindex indicating the order of SC-FDMA symbols. It is assumed that thesample index is increased from the left side to the right side of eachlayer and the SC-FDMA symbol index is increased from the upper side tothe lower side. The numeral in block indicates the order of bit vectorsof the encoded code blocks or the order of corresponding modulationvalues.

Hereinafter, a method of allocating resources for transmitting an uplinksignal in a MIMO wireless communication system in the case where thenumber of transmission antennas is 2 or 4 will be described. Thefollowing resource allocation method is only exemplary and otherembodiments are possible.

<Case where the Number of Transmission Antennas is 2>

FIG. 9 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a single codeword scheme is used. In particular, FIG. 9 shows thecase where one TB is segmented into three code blocks, and the codeblocks are encoded and are transmitted with Rank 2.

First, FIG. 9(a) shows a scheme of transmitting encoded code blocksusing resources of a spatial domain and resources of a frequency domainand then using resources of a time domain. Referring to FIG. 9(a), allthe resources of the spatial domain in the resources of one frequencydomain are used and the resources of a next frequency domain are used.In this scheme, the code blocks are distinguished in the time domain.

FIG. 9(b) shows a scheme of using the resources of the time domain inthe resources of one spatial domain and then using the resources of thefrequency domain. The spatial domain which remains after transmittingone code block is used for transmission of a next code block. Inaddition, after all the resources of one spatial domain are used, theresources of a next spatial domain are used. The code blocks aredistinguished within one spatial domain using the frequency. If thenumber of code blocks is an even number, one code block does not use theresources of two spatial domains. However, if the number of code blocksis an odd number, at least one code block uses the resources of twospatial domains.

FIG. 9(c) shows a scheme in which one code block first uses theresources of the time domain in one spatial domain, uses the resourcesof the time domain in a next spatial domain, and uses the resources ofthe frequency domain. In addition, FIG. 9(d) shows a scheme in which onecode block uses the resources of the frequency domain after using theresources of the spatial domain, and the resources of the time domain inthis order. In FIGS. 9(c) and 9(d), the code blocks are distinguishedwithin one spatial domain using the frequency.

FIG. 10 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a multi-codeword scheme is used. In particular, FIG. 10 shows thecase where two TBs are respectively segmented into three code blocks andtwo code blocks, and the code blocks are encoded and are transmittedwith Rank 2. That is, in FIG. 10, CB1, CB2 and CB3 are code blockssegmented from one TB and CB4 and CB5 are code blocks segmented fromanother TB.

First, FIG. 10(a) shows a scheme in which TBs are transmitted using theresources of the spatial domain, and the code blocks segmented from eachof the TBs are transmitted using the resources of the frequency domainand then are transmitted using the resources of the time domain, thatis, a scheme in which the TBs are transmitted using different spatialresources, all the resources of the frequency domain included in theresources of one time domain are used and then the resources of a nexttime domain are used. According to the scheme of FIG. 10(a), the TBs aredistinguished in the spatial domain and the code blocks corresponding toeach of the TBs are distinguished in the time domain.

FIG. 10(b) shows a case where TBs are transmitted using the resources ofthe spatial domain, code blocks segmented from each of the TBs aretransmitted using the resources of the time domain and then aretransmitted using the resources of the frequency domain. According tothe scheme of FIG. 10(b), the TBs are distinguished in the spatialdomain and the code blocks corresponding to each of the TBs aredistinguished in the frequency domain.

FIG. 11 is a diagram showing another example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is twoand a multi-codeword scheme is used. In particular, FIG. 11 shows thecase where each of two TBs is segmented into two code blocks, and thecode blocks are encoded in the code block units and are transmitted withRank 2. That is, in FIG. 11, CB1 and CB2 are code blocks segmented fromone TB and CB3 and CB4 are code blocks segmented from another TB.

In particular, FIG. 11 shows the case where the resources of the timedomain and the resources of the frequency domain are allocated in thisorder and the resources of the spatial domains are shifted as the indexof the resource of the time domain is increased. FIG. 11(b) shows thecase where the resources of the time domain are allocated in the unit oftwo SC-FDMA symbols.

Referring to FIG. 11, code blocks are uniformly distributed in thespatial domain so as to acquire diversity gain. In view of one symbol,since the code blocks segmented from one TB are present in one layer,reception performance can be improved using an interference eliminatingscheme for eliminating a signal received through another layer.

<Case where the Number of Transmission Antennas is Four>

FIGS. 12A and 12B are diagrams showing an example of a method ofallocating resources to an uplink signal according to an embodiment ofthe present invention, in the case where the number of transmissionantennas is four and a single codeword scheme is used. In particular,FIGS. 12A and 12B show the case where one TB is segmented into threecode blocks, and the code blocks are encoded and are transmitted withRank 4.

First, FIG. 12A(a) shows a scheme of using the resources of the timedomain after transmitting encoded code blocks using the resources of thespatial domain and the resources of the frequency domain. Referring toFIG. 12A(a), all the resources of the spatial domain in the resources ofone frequency domain are used and the resources of a next frequencydomain are then used. In this scheme, the code blocks are distinguishedin the time domain.

FIG. 12A(b) shows a scheme of using the resources of the time domain andthen using the resources of the frequency domain. The spatial domainwhich remains after transmitting one code block is used for transmissionof a next code block. In addition, after all the resources of onespatial domain are used, the resources of a next spatial domain areused. The code blocks are distinguished within one spatial domain usingthe frequency.

FIG. 12B(a) shows a scheme in which one code block uses the resources ofthe frequency domain after using the resources of the spatial domain andthe resources of the time domain in this order. In addition, FIG. 12B(b)shows a scheme in which one code block first uses the resources of thetime domain in one spatial domain, uses the resources of the time domainin a next spatial domain, and then uses the resources of the frequencydomain. In FIGS. 12B(a) and 12B(b), the code blocks are distinguishedwithin one spatial domain using the frequency.

Hereinafter, the case where the number of transmission antennas is fourand a multi-codeword scheme is used will be described. In this case, thedescription is given according to whether the number of transmissionantennas and the number of TBs are equal.

FIG. 13 is a diagram showing an example of a method of allocatingresources to an uplink signal according to an embodiment of the presentinvention, in the case where the number of transmission antennas is fourand a multi-codeword scheme is used. In particular, FIG. 13 shows thecase where the number of TBs is four which is equal to the number oftransmission antennas. Since one TB is transmitted using one layer, thecode blocks segmented from one TB are not transmitted using differentlayers.

In FIG. 13, it is assumed that four TBs are respectively segmented intothree code blocks, two code blocks, one code block and two code blocksand are transmitted with Rank 4. That is, in FIG. 13, CB1, CB2 and CB3are code blocks segmented from a first TB, CB4 and CB5 are code blockssegmented from a second TB, CB6 is a code block segmented from a thirdTB, CB7 and CB8 are code blocks segmented from a fourth TB.

In FIG. 13(a), the code blocks transmitted using the respective layersare transmitted using the resources of the time domain and then aretransmitted using the resources of the frequency domain.

Next, the case where the number of transmission antennas and the numberof TBs are different will be described.

In the case where the number of transmission antennas and the number ofTBs are different, the code blocks segmented from one TB are transmittedin a state of being mapped to several layers, as in the single codewordscheme. In the present invention, the case where two TBs are mapped to amaximum of four layers is considered.

First, as transmission using one layer, the TB may be transmitted usingthe resource allocation method corresponding to one layer as shown inFIG. 10(a) or 10(b).

Second, as transmission using two layers, one TB may be transmitted andthe segmented code blocks may be transmitted using the resourceallocation method shown in FIG. 9 or two TBs may be transmitted and thecode blocks segmented from each of the TBs may be transmitted using theresource allocation method shown in FIG. 10.

Third, as transmission using three layers, it is assumed that two TBsare transmitted. One TB may be transmitted using the resource allocationmethod corresponding to one layer as shown in FIG. 10(a) or 10(b), as intransmission using one layer, and another TB may be transmitted usingthe resource allocation method shown in FIG. 9.

Fourth, as transmission using four layers, it is assumed that two TBsare transmitted. The code blocks segmented from each of the TBs may betransmitted using the resource allocation method shown in FIG. 9.

FIG. 14 is a diagram showing an example of a resource allocation methodaccording to an embodiment of the present invention, in the case whereeach of two TBs is segmented into three code blocks, is encoded and istransmitted with Rank 4. In particular, in FIG. 14, CB1, CB2 and CB3denote the code blocks segmented from TB1 and CB4, CB5 and CB6 denotethe code blocks segmented from TB2.

First, FIG. 14(a) shows a scheme of alternately using the resources ofthe spatial domain in the symbol units. In the case where one TB istransmitted using N layers, the resources of the spatial domain to whichone TB is allocated are shifted in the units of N layers and transmittedin a next transport symbol. That is, CB1, CB2 and CB3 segmented from oneTB are transmitted using Layer 1 and Layer 2 in a first symbol of FIG.14(a), but are shifted and transmitted using Layer 3 and Layer 4 in asecond symbol.

FIG. 14(b) shows a scheme of alternately using the resources of thespatial domain in the symbol units, in which, although one TB istransmitted using N layers, the resources of the spatial domain arealternately used in the units of one layer. As can be seen from FIG.14(b), CB1, CB2 and CB3 segmented from one TB are transmitted usingLayer 1 and Layer 2 in a first symbol, but are shifted and transmittedusing Layer 2 and Layer 3 in a second symbol. In this case, the codeblocks are uniformly distributed over the entire spatial domain so as toobtain diversity gain.

FIG. 15 is a diagram showing another example of a resource allocationmethod, in the case where each of two TBs is segmented into three codeblocks, is encoded and is transmitted with Rank 4.

FIG. 15(a) shows a scheme of alternately using the resources of thespatial domain in the symbol units, in which one TB is shifted in theunits of two layers so as to use the resources of the spatial domainupon transmission. FIG. 15(b) shows the case where one TB is shifted inthe units of one layer so as to use the resources of the spatial domainupon transmission.

According to the resource allocation method shown in FIGS. 14 and 15, inview of one transport symbol, since only the code blocks segmented fromone TB are present in one layer, reception performance can be improvedusing an interference eliminating scheme for eliminating a signalreceived through another layer.

As described above, the shift of the layer units may be performed beforethe DFT or after the IFFT in the transmission of the uplink signal. Morepreferably, the shift of the layer units may be performed before theDFT.

The resource allocation method for transmitting the uplink signal in theMIMO system according to the embodiment of the present invention wasdescribed above. In the current LTE standard document, the method ofallocating resources to the uplink signal is described as an extensionof a method of allocating resources to a downlink signal. That is, it ispreferable that, in the case where the uplink signal is transmitted, thesignal is transmitted by preferentially using the resources of the timedomain. However, the method of transmitting the signal by preferentiallyusing the resources of the frequency domain is described. This will bedescribed as follows.

If the number of modulation symbols which can be transmitted usingscheduled resources is H, the number D of bits which can be transmittedusing the scheduled resources becomes H·log₂ Q. Here, Q denotes amodulation order. For example, Q is 2 in the case of BSPK, Q is 4 in thecase of QPSK, and Q is 16 in the case of 16QAM. The modulation symbolspass through a channel interleaver in order to be mapped to the actualtransmission unit (e.g., Resource Elements (RE)).

It is assumed that the number of columns of the channel interleaver isthe number N_(symb) of symbols for transmitting data included in aspecific time transmission unit. For example, if 14 symbols are presentin the transmission unit of 1 ms and two symbols are used as a referencesymbol for channel estimation, the number C of columns of the channelinterleaver becomes 12 which is equal to the number of data symbolsexcluding the number of reference symbols.

In addition, since the channel interleaver performs interleaving in themodulation symbol units, if the modulation order Q is used, processingis performed in the log₂ Q bit units as expressed by Equation 1.y ₀ =[q ₀ , . . . ,q _(log) ₂ _(Q−1)]^(T) ,y ₁ =[q _(log) ₂ _(Q) , . . .,q _(2 log) ₂ _(Q−1)]^(T) , . . . ,y _(k) =[q _(k·log) ₂ _(Q) , . . . ,q_((k+1)·log) ₂ _(Q−1)]^(T)  Equation 1

In Equation 2, q_(j) denotes an encoded bit.

At this time, the number R of rows of the channel interleaver becomes

$\frac{D}{C} = {\frac{H\;\log_{2}Q}{C}.}$At this time, if

${R^{\prime} = {\frac{R}{\log_{2}Q} = \frac{H}{C}}},$the channel interleaver may be expressed by Equation 2.

$\begin{matrix}\begin{bmatrix}g_{0} & g_{1} & \ldots & g_{C - 1} \\g_{C} & g_{C + 1} & \ldots & g_{{2C} - 1} \\\vdots & \vdots & \ddots & \vdots \\g_{{({R^{\prime} - 1})} \cdot C} & g_{{{({R^{\prime} - 1})} \cdot C} + 1} & \ldots & g_{{R^{\prime} \cdot C} - 1}\end{bmatrix} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Here, g_(k) denotes a vector indicating encoded bit streams forming onemodulation symbol. By Equation 2, the input data of the channelinterleaver is written row by row and is read column by column.

That is, with respect to the input data y_(k), g_(k)=y_(k)=[q_(k log) ₂_(Q), . . . , q_((k+1)·log) ₂ _(Q−1)]^(T) is obtained and the outputbecomes y₀, y_(C), . . . , y_((R′−1)·C), . . . , y₁, . . . , y_(R′·C−2),y_(R′·C−1).

When the symbols are mapped to the resources of the time and frequencydomain after passing through the channel interleaver, if mapping issequentially performed from the resources of the frequency domain, aneffect in which mapping is performed from the resources of the timedomain is obtained, in view of the encoded bit streams. Since the entiresize of the channel interleaver is the number of modulation symbols,which corresponds to a product of the resources of the time domain andthe resources of the frequency domain, a row direction indicates a timedirection, and one row indicates the number of resources of thefrequency domain in one symbol, reading is performed column by columnsuch that an effect in which mapping is performed from the resources ofthe time domain is obtained.

However, when multiple data is simultaneously transmitted using aplurality of spatial layers in the MIMO antenna system using multipletransmission/reception antennas, the channel interleaver should be newlydesigned for efficient resource mapping.

It is assumed that the number of data streams which are simultaneouslytransmitted by encoding one codeword or TB is L. This corresponds to onetransmission coding chain of the single codeword scheme or one codingchain out of several coding chains of the multi-codeword scheme. In thiscase, as shown in FIG. 16, the encoded bit streams need to be mapped tothe resources of the spatial domain in addition to the resources of thetime and frequency domains.

FIG. 16 is a conceptual diagram of data processing of a system usingmultiple transmission/reception antennas. In FIG. 16, a spatialdistribution process serves to distribute modulated data symbols in theresources of the spatial domain.

FIG. 17 is a diagram showing spatial distribution for transmitting datastreams in uplink in a MIMO system according to an embodiment of thepresent invention. In particular, FIG. 17 shows an embodiment of spatialdistribution in which one TB is transmitted using two layers. Referringto FIG. 17, the transmitted symbols are first mapped to the resources ofthe spatial domain in the resources of one frequency domain and then theresources of the time domain are used. Then, mapping is performed usingthe same method with respect to the resources of the frequency domain.

The present invention suggests the structure of the channel interleaverin which code blocks are mapped to several layers one symbol at a timein the time axis as shown in FIG. 17 and then the resources of a nextfrequency domain in the time axis are filled, when the mapping method offilling the resources of the frequency domain and then filling theresources of the next frequency domain in the time axis is used in thecase where the data streams of one TB are transmitted using severallayers. That is, the structure of the channel interleaver, in whichmapping is performed in order of the resources of the spatial domain,the resources of the time domain and the resources of the frequencydomain, is suggested.

First, a method of adjusting the size of an input bit stream vector maybe considered.

In the case where the number of layers used for transmission of one TBis increased to L, the number of resources to which the modulationsymbols may be mapped is increased L-fold. Accordingly, if the number ofmodulation symbols which may be transmitted using one layer is H, thenumber of symbols which may be transmitted using L layers becomes HL. Ifan independent order (1=1, . . . , L) is applied to each layer, thenumber D of bits which may be used to transmit one TB using thescheduled resources becomes

$H \cdot {\sum\limits_{l = 1}^{L}{\log_{2}{Q_{l}.}}}$Accordingly, since the length of the bit streams input to the channelinterleaver is increased, if the size of the vector of the input data isincreased to

${\sum\limits_{l = 1}^{L}{\log_{2}Q_{l}}},$the resources may be efficiently mapped without significantly changingthe configuration, as compared with a channel interleaver for performingtransmission using one layer.

The number C of columns of the interleaver is fixed to N_(symb) and thenumber of rows becomes

$R = {\frac{D}{C} = {\frac{H}{C} \cdot {\sum\limits_{l = 1}^{L}{\log_{2}{Q_{l}.}}}}}$At this time, if

${R^{\prime} = {\frac{R}{\sum\limits_{l = 1}^{L}{\log_{2}Q_{l}}} = \frac{H}{C}}},$the bit stream vector input to the channel interleaver of Equation 2 maybe extended as expressed by Equation 3. The structure of the channelinterleaver of Equation 2 may be applied to the MIMO system withoutchange.y _(k) =[q _(k·log) ₂ _(Q) ₁ ¹ , . . . ,q _((k+1)·log) ₂ _(Q) ₁ ⁻¹ ¹ ,q_(k·log) ₂ _(Q) ₂ ² , . . . ,q _((k+1)·log) ₂ _(Q) ₂ ⁻¹ ² , . . . ,q_(k·log) ₂ _(Q) _(L) ^(L) , . . . ,q _((k+1)·log) ₂ _(Q) _(L) ⁻¹^(L)]^(T)  Equation 3

In Equation 3, q_(k) ^(l) denotes an encoded bit transmitted using anl-th layer. That is, with respect to the input data y_(k), g_(k)=y_(k)is obtained and the output is y₀, y_(C), . . . , y_((R′−1)·C), y₁, . . ., y_(R′·C−2), y_(R′·C−1). The bit vector g_(k) becomes L modulationsymbols, each of which is composed of log₂ Q_(l) (l=1, . . . , L) bits.

That is, the mapping method shown in FIG. 17 may be performed even usingthe conventional channel interleaver, by adjusting the size of the inputbit stream vector.

As another embodiment, in the case where the modulation orders appliedto all the layers are equal to Q, the input vector becomes Equation 4.y _(k) =[q _(k·log) ₂ _(Q) ¹ , . . . ,q _((k+1)·log) ₂ _(Q−1) ¹ ,q_(k·log) ₂ _(Q) ² , . . . ,q _((k+1)·log) ₂ _(Q−1) ² , . . . ,q _(k·log)₂ _(Q) ^(L) , . . . ,q _((k+1)·log) ₂ _(Q−1) ^(L)]^(T)  Equation 4

If the same modulation order is used in all the layers, that is, Q₁=Q₂=. . . Q_(l)=Q, the number R of rows is

$\frac{D}{C} = \frac{{{HL} \cdot \log_{2}}Q}{C}$and R′ is

$\frac{R}{{L \cdot \log_{2}}Q_{l}} = {\frac{H}{C}.}$

Next, a method of adjusting the number of bit vectors of the channelinterleaver may be considered.

If it is assumed that the number of layers used for transmitting one TBis L, the number of columns of the channel interleaver is N_(symb), andthe modulation order of Q_(l) (l=1, . . . , L) is applied to the layers,the number R of rows becomes

$\frac{D}{C} = {\frac{H}{C} \cdot {\sum\limits_{l = 1}^{L}{\log_{2}{Q_{l}.}}}}$

At this time, if

$R^{\prime} = {\frac{R}{\sum\limits_{l = 1}^{L}{\log_{2}Q_{l}}} = \frac{H}{C}}$is defined, the channel interleaver may be expressed by Equation 5.

$\begin{matrix}{\begin{bmatrix}g_{0}^{1} & g_{1}^{1} & \ldots & g_{C}^{1} \\g_{0}^{2} & g_{1}^{2} & \ldots & g_{C}^{2} \\\vdots & \vdots & \ddots & \vdots \\g_{0}^{l} & g_{1}^{l} & \ldots & g_{C}^{l} \\g_{C}^{1} & g_{C + 1}^{1} & \ldots & g_{{2C} - 1}^{1} \\g_{C}^{2} & g_{C + 1}^{2} & \ldots & g_{{2C} - 1}^{2} \\\vdots & \vdots & \ddots & \vdots \\g_{C}^{l} & g_{C + 1}^{l} & \ldots & g_{{2C} - 1}^{l} \\\vdots & \vdots & \vdots & \vdots \\g_{{({R^{\prime} - 1})} \cdot C}^{1} & g_{{{({R^{\prime} - 1})} \cdot C} + 1}^{1} & \ldots & g_{{R^{\prime} \cdot C} - 1}^{1} \\g_{{({R^{\prime} - 1})} \cdot C}^{2} & g_{{{({R^{\prime} - 1})} \cdot C} + 1}^{2} & \ldots & g_{{R^{\prime} \cdot C} - 1}^{2} \\\vdots & \vdots & \ddots & \vdots \\g_{{({R^{\prime} - 1})} \cdot C}^{l} & g_{{{({R^{\prime} - 1})} \cdot C} + 1}^{l} & \ldots & g_{{R^{\prime} \cdot C} - 1}^{l}\end{bmatrix},} & \left\langle {{Equation}\mspace{14mu} 5} \right\rangle\end{matrix}$

In Equation 5, g_(k) denotes a vector indicating bit streams configuringone modulation symbol. If Equation 6 is a bit stream vector transmittedusing an l-th layer, the input of the channel interleaver is g_(k)^(l)=y_(k) ^(l) and the output is performed column by column.y _(k) ^(l) =[q _(k·log) ₂ _(Q) _(l) ^(l) , . . . ,q _((k+1)·log) ₂ _(Q)_(l) ⁻¹ ^(l)]^(T)(l=1, . . . ,L)  Equation 6

At this time, the output of the channel interleaver becomes y₀ ¹, y₀ ²,. . . , y₀ ^(L), y_(C) ¹, y_(C) ², . . . , y_(C) ^(L), . . . , y_(R′C−1)¹, y_(R′C−1) ², . . . , y_(R′C−1) ^(L). That is the mapping method shownin FIG. 17 may be performed by adjusting the number of bit vectors ofthe channel interleaver.

Meanwhile, if the same modulation order is used in all the layers, thatis,

${Q_{1} = {Q_{2} = {{\ldots\mspace{14mu} Q_{1}} = Q}}},{R = {\frac{D}{C} = {\frac{{{HL} \cdot \log_{2}}Q}{C}\mspace{14mu}{and}}}}$$R^{\prime} = {\frac{R}{{L \cdot \log_{2}}Q_{l}} = \frac{H}{C}}$are obtained.

The above description relates to a mapping method when HARQ relatedinformation and control information such as CQI/PMI/RI are nottransmitted together. In the case where user data is transmittedtogether with the HARQ information and the CQI/PMI/RI information,mapping is performed according to the next rule. It is assumed that theCQI/PMI uses the same modulation scheme as the user data. First, afterthe RI information is mapped to a specific location of the channelinterleaver, the user data is mapped to the remaining location of thechannel interleaver, to which the RI information is not mapped. Finally,the HARQ related information is mapped to a specific location. At thistime, data which is mapped to the HARQ related information in advance ispunctured. The locations to which the RI information and the HARQrelated information are mapped do not overlap each other.

FIG. 18 is a diagram showing the configuration of a terminal apparatusaccording to an embodiment of the present invention.

Referring to FIG. 18, the terminal apparatus 1800 includes a processor1810, a memory 1820, an RF module 1830, a display module 1840 and a userinterface module 1850.

The terminal apparatus 1800 is shown for convenience of description andsome modules may be omitted. The terminal apparatus 1800 may furtherinclude necessary modules. In addition, in the terminal apparatus 1800,some modules may be subdivided into sub-modules. The processor 1810 isconfigured to perform an operation according to the embodiment of thepresent invention described with reference to the drawings.

More particularly, the processor 1810 may perform an operation necessaryfor multiplexing a control signal and a data signal. For a detailedoperation of the processor 1810, reference may be made to thedescription of FIGS. 1 to 17.

The memory 1820 is connected to the processor 1810 so as to store anoperating system, applications, program code, data and the like. The RFmodule 1830 is connected to the processor 1810 so as to perform afunction for converting a baseband signal into an RF signal orconverting an RF signal into a baseband signal. The RF module 1830performs analog conversion, amplification, filtering and frequencyup-conversion, or an inverse process thereof. The display module 1840 isconnected to the processor 1810 so as to display a variety ofinformation. The display module 1840 is not limited thereto and a knownelement such as a Liquid Crystal Display (LCD), a Light Emitting Diode(LED) or an Organic Light Emitting Diode (OLED) may be used. The userinterface module 1850 is connected to the processor 1810 and may becomposed of a combination of known user interfaces such as a keypad anda touch screen.

The above-mentioned embodiments of the present invention are proposed bycombining constituent components and characteristics of the presentinvention according to a predetermined format. The individualconstituent components or characteristics should be considered to beoptional factors on the condition that there is no additional remark. Ifrequired, the individual constituent components or characteristics neednot be combined with other components or characteristics. Also, someconstituent components and/or characteristics may be combined toimplement the embodiments of the present invention. The order ofoperations disclosed in the embodiments of the present invention may bechanged to another. Some components or characteristics of any embodimentmay also be included in other embodiments, or may be replaced with thoseof the other embodiments as necessary. It will be apparent thatembodiments may be configured by combining claims without an explicitrelationship therebetween or new claims may be added by amendment afterapplication.

The embodiments of the present invention are described on the basis of adata transmission/reception relationship between a terminal and a basestation. Specific operations to be conducted by the base station in thepresent invention may also be conducted by an upper node of the basestation as necessary. In other words, it will be obvious to thoseskilled in the art that various operations for enabling the base stationto communicate with the terminal in a network composed of severalnetwork nodes including the base station will be conducted by the basestation or other network nodes other than the base station. The term“Base Station” may be replaced with the terms fixed station, Node-B,eNode-B (eNB), or access point as necessary. The term “mobile station”may also be replaced with the terms user equipment (UE), mobile station(MS) or mobile subscriber station (MSS) as necessary.

The embodiments of the present invention can be implemented by a varietyof means, for example, hardware, firmware, software, or a combinationthereof. In the case of implementing the present invention by hardware,the present invention can be implemented with Application SpecificIntegrated Circuits (ASICs), Digital Signal Processors (DSPs), DigitalSignal Processing Devices (DSPDs), Programmable Logic Devices (PLDs),Field Programmable Gate Arrays (FPGAs), a processor, a controller, amicrocontroller, a microprocessor, etc.

If operations or functions of the present invention are implemented byfirmware or software, the present invention can be implemented in theform of a variety of formats, for example, modules, procedures,functions, etc. The software code may be stored in a memory unit so thatit can be driven by a processor. The memory unit is located inside oroutside of the processor, so that it can communicate with theaforementioned processor via a variety of well-known means.

Although a method of allocating resources for transmitting an uplinksignal in a MIMO wireless communication system and an apparatus thereofare applied to a 3GPP LTE system, the method and apparatus may beapplied to various MIMO wireless communication systems for transmittingan uplink signal using a similar DFT process, in addition to the 3GPPLTE system.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method for transmitting an uplink signal usingL layers at a terminal in a multiple-input multiple-output (MIMO)wireless communication system, the method comprising: generating, by theterminal, modulation symbols by modulating output bit sequences of aninterleaver matrix by a unit of log₂ Q bits, wherein Q is a modulationorder, and wherein each of the output bit sequences has a size of L*log₂Q bits and L is a number of layers; mapping, by the terminal, themodulation symbols to the L layers; and transmitting, by the terminal,the modulation symbols by using the L layers.
 2. The method according toclaim 1, wherein the output bit sequences are generated by reading outentries of the interleaver matrix, column by column.
 3. The methodaccording to claim 1, wherein if a number of modulation symbols perlayer is given by H and a number of columns of the interleaver matrix isgiven by C, a number of rows R of the interleaver matrix is defined byEquation 1 shown below: $\begin{matrix}{\frac{{H \cdot L \cdot \log_{2}}Q}{C}.} & \left\langle {{Equation}\mspace{14mu} 1} \right\rangle\end{matrix}$
 4. The method according to claim 3, wherein theinterleaver matrix is represented by Equation 2 shown below:$\begin{matrix}{\begin{bmatrix}g_{0} & g_{1} & \ldots & g_{C - 1} \\g_{C} & g_{C + 1} & \ldots & g_{{2C} - 1} \\\vdots & \vdots & \ddots & \vdots \\g_{{({R^{\prime} - 1})} \cdot C} & g_{{{({R^{\prime} - 1})} \cdot C} + 1} & \ldots & g_{{R^{\prime} \cdot C} - 1}\end{bmatrix},} & \left\langle {{Equation}\mspace{14mu} 2} \right\rangle\end{matrix}$ $R^{\prime} = \frac{R}{{L \cdot \log_{2}}Q}$ wherein andg_(k) is a vector defined by L·log₂ Q rows.
 5. The method according toclaim 4, wherein the vector g_(k) is defined by Equation 3 shown below:g _(k) =[q _(k·log) ₂ _(Q) ¹ , . . . ,q _((k+1)·log) ₂ _(Q−1) ¹ ,q_(k·log) ₂ _(Q) ² , . . . ,q _((k+1)·log) ₂ _(Q−1) ² , . . . ,q _(k·log)₂ _(Q) ^(L) , . . . ,q _((k+1)·log) ₂ _(Q−1) ^(L)]^(T),  <Equation 3>wherein q_(j) denotes an encoded bit.
 6. A terminal apparatus of amultiple-input multiple-output (MIMO) wireless communication system, theterminal apparatus comprising: a processor configured to: generatemodulation symbols by modulating output bit sequences of an interleavermatrix by a unit of log₂ Q bits, wherein Q is a modulation order, andwherein each of the output bit sequences has a size of L·log₂ Q bits andL is a number of layers, and map the modulation symbols to the L layers;and a transmission module configured to transmit the modulation symbolsby using the L layers.
 7. The terminal apparatus according to claim 6,wherein the processor is configured to generate the output bit sequencesby reading out entries of the interleaver matrix, column by column. 8.The terminal apparatus according to claim 6, wherein if a number ofmodulation symbols per layer is given by H and a number of columns ofthe interleaver matrix is given by C, a number of rows R of theinterleaver matrix is defined by Equation 1 shown below: $\begin{matrix}{\frac{{H \cdot L \cdot \log_{2}}Q}{C}.} & \left\langle {{Equation}\mspace{14mu} 1} \right\rangle\end{matrix}$
 9. The terminal apparatus according to claim 8, whereinthe interleaver matrix is represented by Equation 2 shown below:$\begin{matrix}{\begin{bmatrix}g_{0} & g_{1} & \ldots & g_{C - 1} \\g_{C} & g_{C + 1} & \ldots & g_{{2C} - 1} \\\vdots & \vdots & \ddots & \vdots \\g_{{({R^{\prime} - 1})} \cdot C} & g_{{{({R^{\prime} - 1})} \cdot C} + 1} & \ldots & g_{{R^{\prime} \cdot C} - 1}\end{bmatrix},} & \left\langle {{Equation}\mspace{14mu} 2} \right\rangle\end{matrix}$ wherein $R^{\prime} = \frac{R}{{L \cdot \log_{2}}Q}$  andg_(k) is a vector defined by L·log₂ Q rows.
 10. The terminal apparatusaccording to claim 9, wherein the vector g_(k) is defined by Equation 3shown below:g _(k) =[q _(k·log) ₂ _(Q) ¹ , . . . ,q _((k+1)·log) ₂ _(Q−1) ¹ ,q_(k·log) ₂ _(Q) ² , . . . ,q _((k+1)·log) ₂ _(Q−1) ² , . . . ,q _(k·log)₂ _(Q) ^(L) , . . . ,q _((k+1)·log) ₂ _(Q−1) ^(L)]^(T),  <Equation 3>wherein q_(j) denotes an encoded bit.